Xobesin agonists and antagonists for the treatment of metabolic disorders

ABSTRACT

The present invention relates to the field of metabolic research, in particular the discovery of compounds effective for reducing body mass and useful for treating obesity-related diseases and disorders. The obesity-related diseases or disorders envisioned to be treated by the methods of the invention include, but are not limited to, hyperlipidemia, atherosclerosis, insulin resistance, diabetes, and hypertension. In particular, the invention provides for methods of identifying and using AGONISTS and ANTAGONISTS of XOBESIN activity, wherein said activity is selected from the group consisting of lipid partitioning, lipid metabolism, and insulin-like activity.

FIELD OF THE INVENTION

The present invention relates to the field of metabolic research, inparticular the discovery of compounds effective for reducing body massand maintaining weight loss and useful for treating obesity-relateddiseases and disorders. The obesity-related diseases or disordersenvisioned to be treated by the methods of the invention include, butare not limited to, hyperlipidemia, atherosclerosis, insulin resistance,diabetes, and hypertension. The present invention additionally relateselsewhere to the field of metabolic research, in particular thediscovery of compounds effective for increasing body mass and useful fortreating disorders associated with excessive weight loss. Applicantreserves the right to exclude any of the aforesaid obesity-relateddiseases or disorders. The disorders associated with excessive weightloss and envisioned to be treated by the methods of the inventioninclude, but are not limited to, cachexia, cancer-related weight loss,AIDS-related weight loss, chronic inflammatory disease-related weightloss, and anorexia. Applicant reserves the right to exclude any of theaforesaid disorders associated with excessive weight loss.

In particular, the invention provides for methods of identifying andusing AGONISTS and ANTAGONISTS of XOBESIN activity, wherein saidactivity is selected from the group consisting of lipid partitioning,lipid metabolism, and insulin-like activity.

BACKGROUND OF THE INVENTION

The following discussion is intended to facilitate the understanding ofthe invention, but is not intended nor admitted to be prior art to theinvention.

Obesity is a public health problem that is serious, widespread, andincreasing. In the United States, 20 percent of the population is obese;in Europe, a slightly lower percentage is obese (Friedman (2000) Nature404:632-634). Obesity is associated with increased risk of hypertension,cardiovascular disease, diabetes, and cancer as well as respiratorycomplications and osteoarthritis (Kopelman (2000) Nature 404:635-643).Even modest weight loss ameliorates these associated conditions.Recently it was shown that particular carboxyl-terminal fragments of thefull-length ACRP30 (mouse) and APM1 (human) polypeptides have unexpectedeffects in vitro and in vivo, including utility for weight reduction,prevention of weight gain, and control of blood glucose levels (Fruebiset al (2001) Proc Natl Acad Sci USA 98:2005-10). The effects of ACRP30fragment administration in mammals also include reduction of elevatedfree fatty acid levels including elevated free fatty acid levels causedby administration of epinephrine, iv. injection of “intralipid”, oradministration of a high fat test meal, as well as increased fatty acidoxidation in muscle cells, and weight reduction in mammals consuming anormal or high fat/high sucrose diet.

Throughout this application, various publications, patents and publishedpatent applications are cited. The disclosures of these publications,patents and published patent specification referenced in thisapplication are hereby incorporated by reference into the presentdisclosure to more fully describe the state of the art to which thisinvention pertains.

SUMMARY OF THE INVENTION

APM1 belongs to an expanding family of related secreted polypeptidesthat includes among others C2P, ZADJ-2 and ZADJ-7. These polypeptideshave in common the structure: signal peptide, N-terminally disposedunique region, collagen-like region, and globular C-terminal C1qhomology domain. APM1, C2P, ZADJ-2 and ZADJ-7 further share an NGLXXDamino acid motif C-terminally disposed within the globular domain withina loop implicated in receptor binding, wherein said receptor is XOBESIN.Fragments of APM1, C2P, ZADJ-2 and ZADJ-7 polypeptide comprising theglobular domain are herein referred to as gAPM1, gC2P, gZADJ-2 andgZADJ-7. It is further taken to be understood herein that LIGAND refersto a composition consisting essentially of or consisting of in vitro orin vivo self-assembling homotrimer comprised of gAPM1, gC2P, gZADJ-2, orgZADJ-7 polypeptide fragment.

XOBESIN is a member of the Tumor Necrosis Factor Receptor Super Family(TNFRSF) and is a Type I transmembrane protein. The instant invention isbased on XOBESIN as receptor for LIGAND that mediates effects, includingutility for weight reduction, maintenance of weight loss, prevention ofweight gain, increased insulin sensitivity, and control of blood glucoselevels in humans and other mammals. These effects in mammals of XOBESINengagement by LIGAND also include reduction of elevated free fatty acidlevels including elevated free fatty acid levels including elevated freefatty acid levels caused by administration of epinephrine, i.v.injection of “intralipid”, or administration of a high fat test meal, aswell as increased fatty acid oxidation in muscle cells, and weightreduction in mammals consuming a normal or high fat/high sucrose diet.More specifically, the present invention is directed to XOBESIN to whichLIGAND binds and through which LIGAND mediates said effects.

In particular, the invention provides for methods of identifying andusing AGONISTS and ANTAGONISTS of XOBESIN activity, wherein saidactivity is selected from the group consisting of lipid partitioning,lipid metabolism, and insulin-like activity, as well as topharmaceutical and physiologically acceptable compositions comprisingsaid XOBESIN AGONISTS or ANTAGONISTS and methods of administering saidpharmaceutical and physiologically acceptable compositions in order toincrease or reduce body weight, maintain weight loss, or to treatobesity-related diseases and disorders. Assays for identifying AGONISTSand ANTAGONISTS of obesity-related activity are also part of theinvention.

Preferably said XOBESIN AGONIST or ANTAGONIST is a compound selectedfrom the group consisting of polypeptide, polypeptide fragment, peptide,protein, antibody, carbohydrate, lipid, small molecular weight organiccompound and small molecular weight inorganic compound.

Preferably said XOBESIN AGONIST or ANTAGONIST is a compound thatselectively binds to the extracellular domain of XOBESIN.

In other embodiment, said XOBESIN AGONIST or ANTAGONIST is a compoundthat selectively binds to the intracellular domain of a polypeptidecomprising the extracellular domain of XOBESIN.

The present invention also provides a method of assaying test compoundsto identify a test compound that binds to XOBESIN polypeptide. Themethod comprises contacting XOBESIN polypeptide with a test compound andto determine the extent of binding of the test compound to said XOBESINpolypeptide. The method further comprises determining whether such testcompounds are AGONISTS or ANTAGONISTS of XOBESIN polypeptide. Thepresent invention further provides a method of testing the impact ofmolecules on the expression of XOBESIN polypeptide or on the activity ofXOBESIN polypeptide.

The present invention also relates to diagnostic methods of identifyingindividuals or non-human animals having elevated or reduced levels ofXOBESIN products, which individuals are likely to benefit from therapiesto suppress or enhance XOBESIN expression, respectively, and to methodsof identifying individuals or non-human animals at increased risk fordeveloping, or present state of having, certain diseases/disordersassociated with XOBESIN abnormal expression or biological activity.

The present invention provides for methods of identifying AGONISTS ofXOBESIN polypeptide biological activity comprising contacting a smallmolecule compound with XOBESIN polypeptides and measuring XOBESINpolypeptide biological activity in the presence and absence of thesesmall molecules. The present invention further provides for methods ofidentifying ANTAGONISTS of XOBESIN polypeptide biological activitycomprising contacting a small molecule compound with XOBESINpolypeptides and measuring XOBESIN polypeptide biological activity inthe presence and absence of these small molecules. These small moleculescan be a naturally occurring medicinal compound or derived fromcombinatorial chemical libraries.

The present invention also relates to pharmaceutical or physiologicallyacceptable compositions comprising, an active agent, including AGONISTor ANTAGONIST of the present invention.

In a first aspect, the invention is directed to XOBESIN AGONISTS,wherein said AGONIST is an antibody that specifically binds XOBESIN, acompound excluding said XOBESIN antibody (e.g., small organic orinorganic compound, protein, peptide, carbohydrate, lipid), or a LIGANDpolypeptide or fragment thereof.

In a further preferred embodiment, the invention is directed to aXOBESIN AGONIST, wherein said AGONIST is an antibody that specificallybinds XOBESIN. More preferably the invention is directed to said XOBESINantibody, wherein said XOBESIN antibody binds XOBESIN and manifestsLIGAND activity, wherein said activity is selected from the groupconsisting of lipid partitioning, lipid metabolism, and insulin-likeactivity or described herein.

In a further preferred embodiment, the invention is directed to aXOBESIN AGONIST, wherein said AGONIST is a compound excluding saidXOBESIN antibody. More preferably the invention is directed to saidcompound, wherein said compound binds XOBESIN and manifests LIGANDactivity, wherein said activity is selected from the group consisting oflipid partitioning, lipid metabolism, and insulin-like activity ordescribed herein. Further more preferably the invention is directed tosaid compound, wherein said compound manifests LIGAND activity exclusiveof binding to XOBESIN, wherein said activity is selected from the groupconsisting of lipid partitioning, lipid metabolism, and insulin-likeactivity or described herein. Further more preferably the invention isdirected to said compound, wherein said compound increases XOBESINexpression.

In a further preferred embodiment, the invention is directed to aXOBESIN AGONIST that selectively binds to a polypeptide comprising theextracellular domain of XOBESIN.

In a further preferred embodiment, the invention is directed to aXOBESIN AGONIST, wherein said AGONIST is LIGAND, and wherein it isunderstood that LIGAND refers to a composition consisting essentially ofor consisting of in vitro or in vivo self-assembling homotrimercomprised of gAPM1, gC2P, gZADJ-2, or gZADJ-7 polypeptide fragment. Morepreferably the invention is directed to said LIGAND, wherein said LIGANDbinds XOBESIN and elicits biological activity, wherein said activity isselected from the group consisting of lipid partitioning, lipidmetabolism, and insulin-like activity or described herein. Morepreferably the invention is directed to said LIGAND, wherein said LIGANDinduces, enhances, or potentiates said biological activity exclusive ofbinding to XOBESIN. In preferred embodiment, said homotrimer iscomprised of preferred gAPM1, gC2P, gZADJ-2 or gZADJ-7 polypeptidefragment APM1. Preferred gAPM1 polypeptide fragment is selected fromamino acids 18-244, 34-244, 49-244, 56-244, 59-244, 66-244, 69-244,78-244, 85-244, 93-244, 101-244, 102-244, 103-244, 104-244, 107-244,110-244 or 113-244, wherein said numbering of said amino acids withinAPM1 amino acid sequence is understood to be taken from said APM1 aminoacid sequence presented in Table 2. Less preferred gAPM1 fragments areindicated in bold.

C2P. Preferred gC2P polypeptide fragment is selected from amino acids20-333, 25-333, 43-333, 45-333, 46-333, 50-333, 53-333, 61-333, 67-333,74-333, 75-333, 77-333, 81-333, 82-333, 86-333, 89-333, 95-333, 100-333,104-333, 113-333, 116-333, 125-333, 128-333, 140-333, 160-333, 164-333,179-333, 182-333, 185-333, 188-333, 191-333, 193-333, or 202-333,wherein said numbering of said amino acids within C2P amino acidsequence is understood to be taken from said C2P amino acid sequencepresented in Table 2. Less preferred gC2P fragments are indicated inbold.

ZADJ-2. Preferred gZADJ-2 polypeptide fragment is selected from aminoacids 16-285, 25-285, 26285, 29-285, 30-285, 91-285, 93-285, 97-285,98-285, 99-285, 105-285, 109-285, 112-285, 120-285, 126-285, 127-285,130-285, 132-285, 133-285, 134-285, or 150-285, wherein said numberingof said amino acids within ZADJ-2 amino acid sequence is understood tobe taken from said ZADJ-2 amino acid sequence presented in Table 2. Lesspreferred gZADJ-2 fragments are indicated in bold.

ZADJ-7. Preferred gZADJ-7 polypeptide fragment is selected from aminoacids 31-303, 39-303, 78-303, 81-303, 84-303, 85-303, 88-303, 91-303,97-303, 99-303, 109-303, 117-303, 118-303, 127-303, 139-303, 142-303,155-303, or 162-303, wherein said numbering of said amino acids withinZADJ-7 amino acid sequence is understood to be taken from said ZADJ-7amino acid sequence presented in Table 2. Less preferred gZADJ-7fragments are indicated in bold.

More preferred LIGAND is APM1.

In a further preferred embodiment, said AGONIST is able to lowercirculating (either blood, serum or plasma) levels (concentration) of:(i) free fatty acids, (ii) glucose, and/or (iii) triglycerides.

Further preferred AGONISTS are those that significantly stimulate musclelipid or free fatty acid oxidation as compared to untreated cells.Further preferred AGONISTS are those that cause C2C12 cellsdifferentiated in the presence of said AGONISTS to undergo at least 10%,20%, 30%, 35%, or 40% more oleate oxidation as compared to untreatedcells.

Further preferred AGONISTS are those that increase by at least 10%, 20%,30%, 35%, or 40% leptin uptake in a liver cell line [preferably BPRCLmouse liver cells (ATCC CRL-2217)] as compared to untreated cells.

Further preferred AGONISTS are those that significantly reduce thepostprandial increase in plasma free fatty acids or triglycerides,particularly following a high fat meal.

Further preferred AGONISTS are those that significantly reduce oreliminate ketone body production, particularly following a high fatmeal.

Further preferred AGONISTS are those that increase glucose uptake inskeletal muscle cells.

Further preferred AGONISTS are those that increase glucose uptake inadipose cells.

Further preferred AGONISTS are those that increase glucose uptake inneuronal cells.

Further preferred AGONISTS are those that increase glucose uptake in redblood cells.

Further preferred AGONISTS are those that increase glucose uptake in thebrain.

Further preferred AGONISTS are those that significantly reduce thepostprandial increase in plasma glucose following a meal, particularly ahigh carbohydrate meal.

Further preferred AGONISTS are those that significantly prevent thepostprandial increase in plasma glucose following a meal, particularly ahigh fat or a high carbohydrate meal.

Further preferred AGONISTS are those that improve insulin sensitivity.

Further preferred said AGONISTS are those that decrease body mass,wherein said decrease in body mass is comprised of a change in mass ofthe subcutaneous adipose tissue.

Further preferred said AGONISTS are those that decrease body mass,wherein said decrease in body mass is comprised of a change in mass ofthe visceral (omental) adipose tissue.

In a second aspect, the invention features a pharmaceutical orphysiologically acceptable composition comprising, consistingessentially of, or consisting of, said AGONIST described in the firstaspect and, alternatively, a pharmaceutical or physiologicallyacceptable diluent.

In a third aspect, the invention features a method of reducing body masscomprising providing or administering to individuals in need of reducingbody mass said pharmaceutical or physiologically acceptable compositiondescribed in the second aspect.

In a fourth aspect, the invention features a method of preventing ortreating an obesity-related disease or disorder comprising providing oradministering to an individual in need of such treatment saidpharmaceutical or physiologically acceptable composition described inthe second aspect. Preferably, said obesity-related disease or disorderis selected from the group consisting of obesity, insulin resistance,atherosclerosis, atheromatous disease, heart disease, hypertension,stroke, Syndrome X, Noninsulin Dependent Diabetes Mellitus (NIDDM, orType II diabetes) and Insulin Dependent Diabetes Mellitus (IDDM or TypeI diabetes). Diabetes-related complications to be treated by the methodsof the invention include microangiopathic lesions, ocular lesions,retinopathy, neuropathy, and renal lesions. Heart disease includes, butis not limited to, cardiac insufficiency, coronary insufficiency, andhigh blood pressure. Other obesity-related disorders to be treated bysaid XOBESIN AGONIST of the invention include hyperlipidemia andhyperuricemia. In preferred embodiments, said individual is a mammal,preferably a human.

In related aspects, embodiments of the present invention includesmethods of causing or inducing a desired biological response in anindividual comprising the steps of: providing or administering to anindividual a composition comprising AGONIST, wherein said biologicalresponse is selected from the group consisting of:

-   -   (a) lowering circulating (either blood, serum, or plasma) levels        (concentration) of free fatty acids;    -   (b) lowering circulating (either blood, serum or plasma) levels        (concentration) of glucose;    -   (c) lowering circulating (either blood, serum or plasma) levels        (concentration) of triglycerides;    -   (d) stimulating muscle lipid or free fatty acid oxidation;    -   (c) increasing leptin uptake in the liver or liver cells;    -   (e) reducing the postprandial increase in plasma free fatty        acids, particularly following a high fat meal;    -   (f) reducing or eliminating ketone body production, particularly        following a high fat meal;    -   (g) increasing tissue sensitivity to insulin, particularly        muscle, adipose, liver or brain, and further wherein said        biological response is significantly greater than, or at least        10%, 20%, 30%, 35%, or 40% greater than that observed in the        absence of treatment; or alternatively wherein said biological        response is greater than a transient response; or alternatively        wherein said biological response is sustained. In further        preferred embodiments, the present invention of said        pharmaceutical or physiologically acceptable composition can be        used as a method to control blood glucose in some persons with        Noninsulin Dependent Diabetes Mellitus (NIDDM, Type II diabetes)        in combination with insulin therapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to control blood glucose in some persons with Insulin DependentDiabetes Mellitus (IDDM, Type I diabetes) in combination with insulintherapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to control body weight in some persons with NoninsulinDependent Diabetes Mellitus (NIDDM, Type II diabetes) in combinationwith insulin therapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to control body weight in some persons with Insulin DependentDiabetes Mellitus (IDDM, Type I diabetes) in combination with insulintherapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to control blood glucose in some persons with NoninsulinDependent Diabetes Mellitus (NIDDM, Type II diabetes) alone, withoutcombination of insulin therapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to control blood glucose in some persons with Insulin DependentDiabetes Mellitus (IDDM, Type I diabetes) alone, without combination ofinsulin therapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to control body weight in some persons with NoninsulinDependent Diabetes Mellitus (NIDDM, Type II diabetes) alone, withoutcombination of insulin therapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to control body weight in some persons with Insulin DependentDiabetes Mellitus (IDDM, Type I diabetes) alone, without combination ofinsulin therapy.

In a further preferred embodiment, the present invention may be used incomplementary therapy of NIDDM patients to improve their weight orglucose control in combination with an insulin secretagogue or aninsulin sensitising agent. Preferably, the insulin secretagogue is1,1-dimethyl-2-(2-morpholino phenyl)guanidine fumarate (BTS67582) or asulphonylurea selected from tolbutamide, tolazamide, chlorpropamide,glibenclamide, glimepiride, glipizide and glidazide. Preferably, theinsulin sensitising agent is selected from metformin, ciglitazone,troglitazone and pioglitazone.

The present invention further provides a method of improving the bodyweight or glucose control of NIDDM patients alone, without an insulinsecretagogue or an insulin sensitising agent.

In a further preferred embodiment, the present invention may be used incomplementary therapy of IDDM patients to improve their weight orglucose control in combination with an insulin secretagogue or aninsulin sensitising agent. Preferably, the insulin secretagogue is1,1-dimethyl-2-(2-morpholino phenyl)guanidine fumarate (BTS67582) or asulphonylurea selected from tolbutamide, tolazamide, chlorpropamide,glibenclamide, glimepiride, glipizide and glidazide. Preferably, theinsulin sensitising agent is selected from metformin, ciglitazone,troglitazone and pioglitazone.

The present invention further provides a method of improving the bodyweight or glucose control of IDDM patients alone, without an insulinsecretagogue or an insulin sensitising agent.

In a further preferred embodiment, the present invention may beadministered either concomitantly or concurrently, with the insulinsecretagogue or insulin sensitising agent for example in the form ofseparate dosage units to be used simultaneously, separately orsequentially (either before or after the secretagogue or either beforeor after the sensitising agent). Accordingly, the present inventionfurther provides for a composition of pharmaceutical or physiologicallyacceptable composition and an insulin secretagogue or insulinsensitising agent as a combined preparation for simultaneous, separateor sequential use for the improvement of body weight or glucose controlin NIDDM or IDDM patients.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition furtherprovides a method for the use as an insulin sensitiser.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to improve insulin sensitivity in some persons with NoninsulinDependent Diabetes Mellitus (NIDDM, Type II diabetes) in combinationwith insulin therapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to improve insulin sensitivity in some persons with InsulinDependent Diabetes Mellitus (IDDM, Type I diabetes) in combination withinsulin therapy.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition can be used asa method to improve insulin sensitivity in some persons with NoninsulinDependent Diabetes Mellitus (NIDDM, Type II diabetes) without insulintherapy.

In a fifth aspect, the invention features a use of AGONIST described inthe first aspect for treatment of obesity-related diseases and disordersand/or reducing body mass. Preferably, said obesity-related diseases anddisorders are selected from the group consisting of obesity, insulinresistance, atherosclerosis, atheromatous disease, heart disease,hypertension, stroke, Syndrome X, Noninsulin Dependent Diabetes Mellitus(NIDDM, or Type II diabetes) and Insulin Dependent Diabetes Mellitus(IDDM or Type I diabetes). Diabetes-related complications to be treatedby the methods of the invention include microangiopathic lesions, ocularlesions, retinopathy, neuropathy, and renal lesions. Heart diseaseincludes, but is not limited to, cardiac insufficiency, coronaryinsufficiency, and high blood pressure. Other obesity-related disordersto be treated by said AGONIST of the invention include hyperlipidemiaand hyperuricemia.

In a sixth aspect, the invention features a use of AGONIST described inthe first aspect for the preparation of a medicament for the treatmentof obesity-related diseases and disorders and/or for reducing body mass.Preferably, said obesity-related disease or disorder is selected fromthe group consisting of obesity, insulin resistance, atherosclerosis,atheromatous disease, heart disease, hypertension, stroke, Syndrome X,Noninsulin Dependent Diabetes Mellitus (NIDDM, or Type II diabetes) andInsulin Dependent Diabetes Mellitus (IDDM or Type I diabetes).Diabetes-related complications to be treated by the methods of theinvention include microangiopathic lesions, ocular lesions, retinopathy,neuropathy, and renal lesions. Heart disease includes, but is notlimited to, cardiac insufficiency, coronary insufficiency, and highblood pressure. Other obesity-related disorders to be treated bycompounds of the invention include hyperlipidemia and hyperuricemia. Inreferred embodiments, said individual is a mammal, preferably a human.

In a seventh aspect, the invention provides AGONIST of the first aspectof the invention, or a composition of the second aspect of theinvention, for use in a method of treatment of the human or animal body.

In an eighth aspect, the invention features methods of reducing bodyweight comprising providing to an individual said pharmaceutical orphysiologically acceptable composition described in the second aspect,or AGONIST described in the first aspect. Where the reduction of bodyweight is practiced for cosmetic purposes, the individual has a BMI ofat least 20 and no more than 25. In embodiments for the treatment ofobesity, the individual may have a BMI of at least 20. One embodimentfor the treatment of obesity provides for the treatment of individualswith BMI values of at least 25. Another embodiment for the treatment ofobesity provides for the treatment of individuals with BMI values of atleast 30. Yet another embodiment provides for the treatment ofindividuals with BMI values of at least 40.

In further embodiment, the invention features methods of maintainingweight loss comprising providing to an individual said pharmaceutical orphysiologically acceptable composition.

In a ninth aspect, the invention features the pharmaceutical orphysiologically acceptable composition described in the second aspectfor reducing body mass and/or for treatment or prevention ofobesity-related diseases or disorders. Preferably, said obesity-relateddisease or disorder is selected from the group consisting of obesity,insulin resistance, atherosclerosis, atheromatous disease, heartdisease, hypertension, stroke, Syndrome X, Noninsulin Dependent DiabetesMellitus (NIDDM, or Type II diabetes) and Insulin Dependent DiabetesMellitus (IDDM or Type I diabetes). Diabetes-related complications to betreated by the methods of the invention include microangiopathiclesions, ocular lesions, retinopathy, neuropathy, and renal lesions.Heart disease includes, but is not limited to, cardiac insufficiency,coronary insufficiency, and high blood pressure. Other obesity-relateddisorders to be treated by compounds of the invention includehyperlipidemia and hyperuricemia. In preferred embodiments, saidindividual is a mammal, preferably a human. In preferred embodiments,the identification of said individuals to be treated with saidpharmaceutical or physiologically acceptable composition comprisesgenotyping LIGAND single nucleotide polymorphisms (SNPs) or measuringLIGAND polypeptide or mRNA levels in clinical samples from saidindividuals. Preferably, said clinical samples are selected from thegroup consisting of blood, serum, plasma, urine, and saliva.

In a tenth aspect, the invention features the pharmaceutical orphysiologically acceptable composition described in the second aspectfor reducing body weight for cosmetic reasons.

In an eleventh aspect, AGONIST of the invention is used in methods oftreating insulin resistance comprising providing to an individual saidpharmaceutical or physiologically acceptable composition described inthe second aspect, or AGONIST described in the first aspect.

In a preferred aspect of the methods above and disclosed herein, theamount of AGONIST administered to an individual is sufficient to bringlevels of XOBESIN activation to their normal levels (levels inindividuals without obesity-related disease or disorder). “Normallevels” of XOBESIN activation may be followed using surrogate markersincluding circulating (either blood, serum or plasma) levels(concentration) of: (i) free fatty acids, (ii) glucose, and/or (iii)triglycerides.

In a twelfth aspect, the invention is directed to a XOBESIN ANTAGONIST,wherein said ANTAGONIST is a soluble fragment of XOBESIN polypeptide, anantibody that specifically binds XOBESIN, a compound excluding saidsoluble fragment of XOBESIN polypeptide and said XOBESIN antibody (e.g.,small molecular weight organic or inorganic compound, protein, peptide,carbohydrate, lipid), or a variant or fragment of LIGAND polypeptide.

In a further preferred embodiment, the invention is directed to aXOBESIN ANTAGONIST, wherein said ANTAGONIST is a soluble fragment ofXOBESIN polypeptide. More preferably the invention is directed topurified, isolated, or recombinant soluble fragments of XOBESINpolypeptide. More preferably the invention is directed to said solublefragment of XOBESIN polypeptide, wherein said soluble fragment bindsLIGAND and blocks LIGAND activity, said activity being selected from thegroup consisting of lipid partitioning, lipid metabolism, andinsulin-like activity or described herein, and wherein said solublefragment of XOBESIN polypeptide does not activate XOBESIN. Preferablysaid soluble fragment of XOBESIN polypeptide blocks or inhibits LIGANDbinding to XOBESIN. In preferred embodiments, said soluble fragment ofXOBESIN polypeptide comprises, consists essentially of, or consists of,at least 6 and not more than 246 consecutive amino acids of SEQ ID NO:2,more preferably of amino acids comprising the extracellular domain ofXOBESIN. Preferred said soluble fragment of XOBESIN comprises theextracellular domain of mature XOBESIN polypeptide. Particularlypreferred soluble fragment of XOBESIN comprises amino acids 30-197,30-199, 30-207, 30-212, 30-224, 30-231, 30-245 or 30-262 of SEQ ID NO:2,where it is understood that amino acid 30 is predicted to be theN-terminal amino acid of the mature XOBESIN polypeptide absent theputative signal peptide. In other preferred embodiments, said solublefragment of XOBESIN polypeptide comprises an amino acid sequence atleast 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%identical to the corresponding consecutive amino acids of SEQ ID NO:2.Further preferred embodiments include heterologous polypeptidescomprising a XOBESIN polypeptide of the invention. In further preferredembodiment, a XOBESIN polypeptide of the invention is conjugated at itsN- or C-terminus to an antibody Fc region or portion thereof.

In a further preferred embodiment, the invention is directed to aXOBESIN ANTAGONIST, wherein said ANTAGONIST is an antibody thatspecifically binds XOBESIN. More preferably the invention is directed tosaid XOBESIN antibody, wherein said XOBESIN antibody binds XOBESIN andblocks LIGAND activity, said activity being selected from the groupconsisting of lipid partitioning, lipid metabolism, and insulin-likeactivity or described herein, and wherein said XOBESIN antibody does notactivate XOBESIN. Preferably said XOBESIN antibody blocks or inhibitsLIGAND binding to XOBESIN.

In a further preferred embodiment, the invention is directed to aXOBESIN ANTAGONIST, wherein said ANTAGONIST is a compound excluding saidsoluble fragment of XOBESIN polypeptide and said XOBESIN antibody (e.g.,small organic molecule, protein, peptide). More preferably the inventionis directed to said compound, wherein said compound binds to XOBESIN andblocks LIGAND activity, said activity being selected from the groupconsisting of lipid partitioning, lipid metabolism, and insulin-likeactivity or described herein, and wherein said compound does notactivate XOBESIN. Preferably said compound that binds to XOBESIN blocksor inhibits LIGAND binding to XOBESIN. Further more preferably theinvention is directed to said compound, wherein said compound blocks orinhibits LIGAND activity exclusive of binding to XOBESIN, said activitybeing selected from the group consisting of lipid partitioning, lipidmetabolism, and insulin-like activity or described herein, and whereinsaid compound does not activate XOBESIN. Further more preferably theinvention is directed to said compound, wherein said compound blocks orinhibits XOBESIN expression and wherein said compound does not haveLIGAND activity, said activity being selected from the group consistingof lipid partitioning, lipid metabolism, and insulin-like activity ordescribed herein, and wherein said compound does not activate XOBESIN.

In a further preferred embodiment, the invention is directed to aXOBESIN ANTAGONIST, wherein said ANTAGONIST is a variant or fragment ofLIGAND polypeptide. More preferably the invention is directed to saidvariant of fragment of LIGAND polypeptide, wherein said variant orfragment of LIGAND polypeptide binds XOBESIN and blocks LIGAND activity,said activity being selected from the group consisting of lipidpartitioning, lipid metabolism, and insulin-like activity or describedherein, and wherein said variant or fragment of LIGAND polypeptide doesnot activate XOBESIN. Preferably said variant or fragment of LIGANDpolypeptide blocks or inhibits LIGAND binding to XOBESIN. Morepreferably the invention is directed to said variant or fragment ofLIGAND polypeptide, wherein said variant or fragment of LIGANDpolypeptide inhibits the induction, enhancement, or potentiation of saidbiological activity exclusive of binding to XOBESIN.

In a further preferred embodiment, the invention is directed to aXOBESIN ANTAGONIST that selectively binds to a polypeptide comprisingthe extracellular domain of XOBESIN.

In a further preferred embodiment, said ANTAGONIST is able to raisecirculating (either blood, serum or plasma) levels (concentration) of:(i) free fatty acids, (ii) glucose, and/or (iii) triglycerides.

Further preferred said ANTAGONISTS are those that significantly inhibitmuscle lipid or free fatty acid oxidation stimulated by its LIGAND.Further preferred said ANTAGONISTS are those that cause C2C12 cellsdifferentiated in the presence of LIGAND to undergo at least 10%, 20%,30%, 35%, or 40% less oleate oxidation as compared to untreated cells.

Further preferred said ANTAGONISTS are those that inhibit by at least10%, 20%, 30%, 35%, or 40% the increase in leptin uptake stimulated byLIGAND polypeptide in a liver cell line [preferably BPRCL mouse livercells (ATCC CRL-2217)] as compared to untreated cells.

Further preferred said ANTAGONISTS are those that significantly increasethe postprandial increase in plasma free fatty acids, particularlyfollowing a high fat meal.

Further preferred said ANTAGONISTS are those that significantly increaseketone body production, particularly following a high fat meal.

Further preferred said ANTAGONISTS are those that decrease glucoseuptake in skeletal muscle cells stimulated by LIGAND.

Further preferred said ANTAGONISTS are those that decrease glucoseuptake in adipose cells stimulated by LIGAND.

Further preferred said ANTAGONISTS are those that decrease glucoseuptake in neuronal cells stimulated by LIGAND.

Further preferred said ANTAGONISTS are those that decrease glucoseuptake in red blood cells stimulated by LIGAND.

Further preferred said ANTAGONISTS are those that decrease glucoseuptake in the brain stimulated by LIGAND.

Further preferred said ANTAGONISTS are those that significantly increasethe postprandial increase in plasma glucose following a meal,particularly a high carbohydrate meal.

Further preferred said ANTAGONISTS are those that significantlyfacilitate the postprandial increase in plasma glucose following a meal,particularly a high fat or a high carbohydrate meal.

Further preferred said ANTAGONISTS are those that reduce the insulinsensitivity stimulated by LIGAND.

Further preferred said ANTAGONISTS are those that increase body mass,wherein said increase in body mass is comprised of a change in mass ofthe subcutaneous adipose tissue.

Further preferred said ANTAGONISTS are those that increase body mass,wherein said increase in body mass is comprised of a change in mass ofthe visceral (omental) adipose tissue.

In a thirteenth aspect, the invention features a pharmaceutical orphysiologically acceptable composition comprising, consistingessentially of, or consisting of, said ANTAGONIST described in thetwelfth aspect and, alternatively, a pharmaceutical or physiologicallyacceptable diluent.

In a fourteenth aspect, the invention features a method of increasingbody mass comprising providing or administering to individuals in needof increasing body mass said pharmaceutical or physiologicallyacceptable composition described in the thirteenth aspect.

In a fifteenth aspect, the invention features a method of preventing ortreating disorders associated with excessive weight loss comprisingproviding or administering to an individual in need of such treatmentsaid pharmaceutical or physiologically acceptable composition describedin the thirteenth aspect. Preferably said disorder is selected from thegroup consisting of cachexia, wasting, cancer-related weight loss,AIDS-related weight loss, chronic inflammatory disease-related weightloss, anorexia, and bulimia. Said disorders associated with excessiveweight loss are comprised of those mediated by tumor necrosis factor(TNFalpha) alone, those mediated by TNFalpha plus one or more additionalfactors, and those mediated only by one or more factors exclusive ofTNFalpha. Said factors include, but are not restricted to, macrophagemigration inhibitory factor, interleukin 1, and interleukin 6. Inpreferred embodiments, said individual is a mammal, preferably a human.

In related aspects, embodiments of the present invention includesmethods of causing or inducing a desired biological response in anindividual comprising the steps of: providing or administering to anindividual a composition comprising ANTAGONIST, wherein said biologicalresponse is selected from the group consisting of:

-   -   (a) raising circulating (either blood, serum, or plasma) levels        (concentration) of free fatty acids (FFA) or triglycerides (TG);    -   (b) raising circulating (either blood, serum or plasma) levels        (concentration) of glucose;    -   (c) raising circulating (either blood, serum or plasma) levels        (concentration) of triglycerides;    -   (d) inhibiting muscle lipid or free fatty acid oxidation;    -   (c) inhibiting leptin uptake in the liver or liver cells;    -   (e) increasing the postprandial increase in plasma free fatty        acids, particularly following a high fat meal; and,    -   (f) increasing or eliminating ketone body production,        particularly following a high fit meal;    -   (g) reducing tissue sensitivity to insulin, particularly muscle,        adipose, liver or brain, and further wherein said biological        response is greater than a transient response; or alternatively        herein said biological response is sustained. In further        preferred embodiments, the present invention of said        pharmaceutical or physiologically acceptable composition can be        used as a method of increasing body mass in some persons with        cachexia, wasting, cancer-related weight loss, AIDS-related        weight loss, chronic inflammatory disease-related weight loss,        anorexia, and bulimia.

In further preferred embodiments, the present invention of saidpharmaceutical or physiologically acceptable composition furtherprovides a method for the use as an insulin de-sensitiser, wherein thesensitivity of a cell or tissue to insulin is reduced.

In a sixteenth aspect, the invention features a method of making theXOBESIN polypeptide described in the twelfth aspect, wherein said methodis selected from the group consisting of proteolytic cleavage,recombinant methodology and artificial synthesis. In a preferredembodiment, proteolytic cleavage is carried out using trypsin, plasmin,or collagenase.

In a seventeenth aspect, the invention features a use of ANTAGONISTdescribed in the twelfth aspect for the preparation of a medicament forthe treatment of disorders associated with excessive weight loss and/orfor increasing body mass. Preferably, said disorder is selected from thegroup consisting of cachexia, wasting, cancer-related weight loss,AIDS-related weight loss, chronic inflammatory disease-related weightloss, anorexia, and bulimia. In preferred embodiments, said individualis a mammal, preferably a human.

In an eighteenth aspect, the invention provides ANTAGONIST of thetwelfth aspect of the invention, or a composition of the thirteenthaspect of the invention, for use in a method of treatment of the humanor animal body.

In a nineteenth aspect, the invention features methods of increasingbody weight comprising providing to an individual said pharmaceutical orphysiologically acceptable composition described in the thirteenthaspect, or ANTAGONIST described in the twelfth aspect. Where theincrease of body weight is practiced for cosmetic purposes, theindividual has a BMI of no greater than 25 and at least 20. Inembodiments for the treatment of disorders associated with excessiveweight loss, the individual may have a BMI no greater than 20. Oneembodiment for the treatment of disorders associated with excessiveweight loss provides for the treatment of individuals with BMI values ofno greater than 15. Alternatively, for increasing the body weight of anindividual, the BMI value should be at least 15 and no more than 20.

In a twentieth aspect, the invention features the pharmaceutical orphysiologically acceptable composition described in the thirteenthaspect for increasing body mass and/or for treatment of disordersassociated with excessive weight loss. Preferably, said disorder isselected from the group consisting of cachexia, wasting, cancer-relatedweight loss, AIDS-related weight loss, chronic inflammatorydisease-related weight loss, anorexia, and bulimia. In preferredembodiments, said individual is a mammal, preferably a human.

In a twenty-first aspect, the invention features the pharmaceutical orphysiologically acceptable composition described in the thirteenthaspect for increasing body weight for cosmetic reasons.

In a preferred aspect of the methods above and disclosed herein, theamount of ANTAGONIST administered to an individual is sufficient tobring levels of XOBESIN activation to their normal levels (levels inhealthy individuals). “Normal levels” of XOBESIN activation may befollowed using surrogate markers including circulating (either blood,serum or plasma) levels (concentration) of: (i) free fatty acids, (ii)glucose, and/or (iii) triglycerides.

BRIEF DESCRIPTION OF TABLES

Table 1 lists known or predicted biologic structural and functionaldomains for the XOBESIN polypeptide of SEQ ID NO:2 of the presentinvention, including the signal peptide, extracellular (EC) domain,transmembrane domain, and intracellular (IC) domain.

Table 2 lists the amino acid sequence of full-length APM1, C2P, ZADJ-2and ZADJ-7 polypeptide. The total number of amino acids is given inparentheses. The predicted signal peptide is indicated in bold. Thecollagen-like region is indicated by dotted line. The region between thepredicted signal peptide and the collagen-like region is theN-terminally disposed unique region. The globular C-terminal C1qhomology domain is indicated by single underline. The NGLXXD amino acidmotif C-terminally disposed within the globular domain is indicated bydouble underline. It is taken to be understood that C2P hereinencompasses variants comprising the substitution of valine formethionine at position 219 and/or the substitution of methionine forvaline at position 301.

Structure of XOBESIN Polypeptide

The full-length XOBESIN polypeptide is comprised of at least 4 distinctregions including:

-   -   1. an N-terminal putative signal peptide comprising amino acids        from about amino acids 1-29 of SEQ ID NO:2;    -   2. an extracellular domain comprising a LIGAND binding portion        and comprising amino acids from about amino acids 30-275 of SEQ        ID NO:2;    -   3. a transmembrane domain comprising amino acids from about        amino acids 276-298 of SEQ D NO:2; and    -   4. an intracellular domain comprising amino acids from about        amino acids 299-299 of SEQ ID NO:2.

BRIEF DESCRIPTION OF SEQUENCE LISTING

SEQ ID NO:1 is the nucleotide sequence of cDNA with an open readingframe which location is indicated as features. When appropriate, thelocations of the potential polyadenylation site and polyadenylationsignal are also indicated.

SEQ ID NO:2 is the amino acid sequence of polypeptide encoded by thecDNA of SEQ ID NO:1.

The appended Sequence Listing is hereby incorporated by reference in itsentirety.

DETAILED DESCRIPTION

Definitions

Before describing the invention in greater detail, the followingdefinitions are set forth to illustrate and define the meaning and scopeof the terms used to describe the invention herein.

The term “isolated” requires that the material be removed from itsoriginal environment (e.g., the natural environment if the material isnaturally occurring).

The term “purified” does not require absolute purity; rather, it isintended as a relative definition. Purification of starting material ornatural material to at least one order of magnitude, preferably two orthree orders, and more preferably four or five orders of magnitude isexpressly contemplated.

As used interchangeably herein, the term “polynucleotide(s)” include RNAor DNA (either single or double stranded, coding, complementary orantisense), or RNA/DNA hybrid sequences of more than one nucleotide ineither single chain or duplex form (although each of the above speciesmay be particularly specified).

The terms “complementary” or “complement thereof” are used herein torefer to the sequences of polynucleotides that are capable of formingWatson & Crick base pairing with another specified polynucleotidethroughout the entirety of the complementary region.

The terms “polypeptide” and “protein”, used interchangeably herein,refer to a polymer of amino acids without regard to the length of thepolymer; thus, peptides, oligopeptides, and proteins are included withinthe definition of polypeptide. This term also does not specify orexclude chemical or post-expression modifications of the polypeptides ofthe invention, although chemical or post-expression modifications ofthese polypeptides may be included excluded as specific embodiments.

As used herein, the terms “recombinant polynucleotide” and“polynucleotide construct” are used interchangeably to refer to linearor circular, purified or isolated polynucleotides that have beenartificially designed and which comprise at least two nucleotidesequences that are not found as contiguous nucleotide sequences in theirinitial natural environment. In particular, these terms mean that thepolynucleotide or cDNA is adjacent to “backbone” nucleic acid to whichit is not adjacent in its natural environment.

The term “recombinant polypeptide” is used herein to refer topolypeptides that have been artificially designed and which comprise atleast two polypeptide sequences that are not found as contiguouspolypeptide sequences in their initial natural environment, or to referto polypeptides which have been expressed from a recombinantpolynucleotide.

As used herein, the term “operably linked” refers to a linkage ofpolynucleotide elements in a functional relationship.

As used herein, the term “non-human animal” refers to any non-humananimal, including insects, birds, rodents and more usually mammals. Boththe terms “animal” and “mammal” expressly embrace human subjects unlesspreceded with the term “non-human”.

The term “domain” refers to an amino acid fragment with specificbiological properties. This term encompasses all known structural andlinear biological motifs.

As used herein, the term “receptor” refers to a polypeptide to which a“ligand” binds and through which said “ligand” elicits a biologicalresponse comprised of biological activities. Said receptor is preferablyXOBESIN of the present invention. Said “ligand” is preferably LIGAND ofthe present invention. By “receptor activation” is intended“ligand”-mediated alteration of said receptor polypeptide, wherein saidalteration is selected from but not limited to the group consisting ofreceptor alterations associated with said biological response.

As used herein, the term “AGONIST” refers to naturally occurring andsynthetic compounds capable of inducing, enhancing, or potentiating abiological response comprised of biological activities.

As used herein, the term “ANTAGONIST” refers to naturally occurring andsynthetic compounds capable of inhibiting a biological response,inhibiting the induction of a biological response, or inhibiting thepotentiation of a biological response, wherein said biological responseis comprised of biological activities.

Without being limited by theory, the compounds/polypeptides of theinvention are capable of modulating the partitioning of dietary lipidsbetween the liver and peripheral tissues, and are thus believed to treat“diseases involving the partitioning of dietary lipids between the liverand peripheral tissues.” The term “peripheral tissues” is meant toinclude muscle and adipose tissue. In preferred embodiments, thecompounds/polypeptides of the invention partition the dietary lipidstoward or away from the muscle. In alternative preferred embodiments,the dietary lipids are partitioned toward or away from the adiposetissue. In other preferred embodiments, the dietary lipids arepartitioned toward or away from the liver. In yet other preferredembodiments, the compounds/polypeptides of the invention increase ordecrease the oxidation of dietary lipids, preferably free fatty acids(FFA) by the muscle. Dietary lipids include, but are not limited totriglycerides and free fatty acids.

Preferred diseases believed to involve the partitioning of dietarylipids include obesity-related diseases and disorders such as obesity,insulin resistance, atherosclerosis, atheromatous disease, heartdisease, hypertension, stroke, Syndrome X, Noninsulin Dependent DiabetesMellitus (NIDDM, or Type II diabetes) and Insulin Dependent DiabetesMellitus (IDDM or Type I diabetes). Diabetes-related complications to betreated by the methods of the invention include microangiopathiclesions, ocular lesions, retinopathy, neuropathy, and renal lesions.Heart disease includes, but is not limited to, cardiac insufficiency,coronary insufficiency, and high blood pressure. Other obesity-relateddisorders to be treated by compounds of the invention includehyperlipidemia and hyperuricemia. Yet other disorders of the inventioninclude disorders associated with excessive weight loss such ascachexia, wasting, cancer-related weight loss, AIDS-related weight loss,chronic inflammatory disease-related weight loss, anorexia, and bulimia.

The terms “comprising”, “consisting of” and “consisting essentially of”may be interchanged for one another throughout the instant application,although each retains its normal definition. The term “having” has thesame meaning as “comprising” and may be replaced with either the term“consisting of” or “consisting essentially of”.

Polypeptides of the Invention

Preferably, polypeptides of the invention are recombinantly producedusing routine expression methods known in the art. The polynucleotideencoding the desired polypeptide is operably linked to a promoter intoan expression vector suitable for any convenient host Both eukaryoticand prokaryotic host systems are used in forming recombinantpolypeptides. The polypeptide is then isolated from lysed cells or fromthe culture medium and purified to the extent needed for its intendeduse.

Consequently, a further embodiment of the present invention is a methodof making a polypeptide, said method comprising the steps of

-   -   a) obtaining a cDNA encoding said polypeptide;    -   b) inserting said cDNA in an expression vector such that the        cDNA is operably linked to a promoter; and    -   c) introducing said expression vector into a host cell whereby        said host cell produces said polypeptide.

In one aspect of this embodiment, the method further comprises the stepof isolating the polypeptide. Another embodiment of the presentinvention is a polypeptide obtainable by the method described in thepreceding paragraph.

The expression vector is any of the mammalian, yeast, insect orbacterial expression systems known in the art. Commercially availablevectors and expression systems are available from a variety of suppliersincluding Genetics Institute (Cambridge, Mass.), Stratagene (La Jolla,Calif.), Promega (Madison, Wis.), and Invitrogen (San Diego, Calif.). Inpreferred embodiment, recombinant polypeptides of the invention areexpressed in mammalian cells.

The invention is drawn, inter alia, to isolated, purified or recombinantpolypeptides. XOBESIN polypeptides of the invention are useful forincreasing (ANTAGONISTS of XOBESIN) body weight either as a cosmetictreatment or for treatment or prevention of diseases and disorders asdiscussed or described herein. XOBESIN polypeptides are also usefulinter alia in screening assays for AGONISTS or ANTAGONISTS of XOBESINactivity and for raising XOBESIN-specific antibodies. When used forcosmetic treatments, or for the treatment or prevention of diseases,disorders, or conditions, one or more XOBESIN polypeptides can beprovided to a subject. Thus, various fragments of the full-lengthprotein can be combined into a “cocktail” for use in the varioustreatment regimens. LIGAND polypeptides of the invention are useful forreducing (AGONISTS of XOBESIN) body weight either as a cosmetictreatment or prevention of diseases and disorders as discussed ordescribed herein.

The XOBESIN polypeptides of the present invention are preferablyprovided in an isolated form, and may be partially or substantiallypurified.

Modifying XOBESIN Biological Activity

Modifying endogenous XOBESIN biological activity is expresslycontemplated by the present invention. The present invention furtherrelates to compounds able to modulate XOBESIN biological activity andmethods to use these compounds. Such compounds may interact with XOBESINpolypeptides directly or indirectly.

Candidate AGONISTS and ANTAGONISTS Obtained by Optical Biosensor Methods

Compounds interacting with a polypeptide comprising XOBESINextracellular domain can be screened by using an Optical Biosensor asdescribed in Edwards and Leatherbarrow (1997) and also in Szabo et al.(1995), the disclosures of which are incorporated by reference. Thistechnique permits the detection of interactions between molecules inreal time, without the need of labeled molecules. This technique, whichis based on the surface plasmon resonance (SPR) phenomenon, is presentedin more detail in Example 1.

Compounds Modulating XOBESIN Biological Activity

Another method of screening for compounds that modulate XOBESINbiological activity is by measuring the effects of test compounds onspecific biological activity, wherein said activity is selected from thegroup consisting of lipid partitioning, lipid metabolism, andinsulin-like activity or as described herein, in a host cell. In oneembodiment, the present invention relates to a method of identifying anagent that alters XOBESIN activity, wherein a nucleic acid constructcomprising the polynucleotide of SEQ ID NO:1 or a fragment thereofencoding full length XOBESIN polypeptide is introduced into a mammalianhost cell. The transfected mammalian host cells are maintained underconditions appropriate for expression of the encoded XOBESIN, wherebythe nucleic acid is expressed. The host cells are then contacted with acompound to be assessed (an agent) and an activity of the cells isdetected in the presence of the compound to be assessed, wherein saidactivity is selected from the group consisting of lipid partitioning,lipid metabolism, and insulin-like activity or as described herein.Detection of a change in said activity for said transfected host cell,but not in untransfected host cell, in the presence of the agentindicates that the agent alters XOBESIN activity. In a particularembodiment, the invention relates to a method of identifying an agentwhich is an activator (AGONIST) of XOBESIN activity, wherein detectionof an increase of said activity, said activity being selected from thegroup consisting of lipid partitioning, lipid metabolism, andinsulin-like activity or as described herein, in the presence of theagent indicates that the agent activates XOBESIN activity. In anotherparticular embodiment, the invention relates to a method of identifyingan agent which is an inhibitor (ANTAGONIST) of XOBESIN activity, whereindetection of a decrease of said activity, said activity being selectedfrom the group consisting of lipid partitioning, lipid metabolism, andinsulin-like activity or as described herein, in the presence of theagent indicates that the agent inhibits XOBESIN activity.

Detection of a change in said XOBESIN activity, said activity beingselected from the group consisting of lipid partitioning, lipidmetabolism, and insulin-like activity or as described herein, can beperformed using a variety of techniques as described for representativeactivities in Examples provided herein.

In a particular embodiment a high throughput screen can be used toidentify agents that activate (enhance) or inhibit XOBESIN activity (Seee.g., PCT publication WO 98/45438, which disclosure is herebyincorporated by reference in its entirety).

Methods of Screening for Compounds Modulating XOBESIN Activity

The present invention also relates to methods of screening compounds fortheir ability to modulate (e.g. increase or inhibit) the activity orexpression of XOBESIN. More specifically, the present invention relatesto methods of testing compounds for their ability either to increase orto decrease activity of XOBESIN. The assays are performed in vitro or invivo.

The present invention relates to a method for the screening of acandidate substance for interaction with a polypeptide comprisingXOBESIN extracellular domain, said method comprising the followingsteps:

-   -   a) providing said polypeptide comprising XOBESIN extracellular        domain;    -   b) obtaining a candidate substance;    -   c) bringing into contact said polypeptide with said candidate        substance;    -   d) detecting the complexes formed between said polypeptide and        said candidate substance.

The invention further relates to a method for the production of apharmaceutical composition comprising a method for the screening of acandidate substance that interact with a XOBESIN polypeptide, fragmentsor variants thereof and furthermore mixing the identified substance witha pharmaceutically acceptable carrier.

The present invention relates to a method for the screening of acandidate substance for the capacity to increase expression of XOBESIN,said method comprising the following steps:

-   -   a) isolating mRNA from cells which have or have not been        contacted with said candidate substance;    -   b) carrying out a Northern blot analysis with labeled cDNA probe        encoding all or part of XOBESIN polypeptide;    -   c) wherein increased signal in cells having been contacted with        said candidate substance over that of uncontacted cells is taken        to indicate that said candidate substance increases expression        of XOBESIN and is an AGONIST of XOBESIN activity; and    -   d) wherein decreased signal in cells having been contacted with        said candidate substance over that of uncontacted cells is taken        to indicate that said candidate substance decreases expression        of XOBESIN and is an ANTAGONIST of XOBESIN activity.        Methods of isolating mRNA and carrying out Northern blot        analysis are well known to those of ordinary skill in the art.

Preparation of Antibody Compositions

Substantially pure protein or polypeptide is isolated from transfectedor transformed cells containing an expression vector encoding theXOBESIN protein or a portion thereof. The concentration of protein inthe final preparation is adjusted, for example, by concentration on anAmicon filter device, to the level of a few micrograms/ml. Monoclonal orpolyclonal antibody to the protein can then be prepared by methods wellknown to those of ordinary skill in the art

Preferably the present invention includes monoclonal and polyclonalantibodies that specifically bind XOBESIN polypeptide fragmentcomprising the extracellular domain of mature XOBESIN polypeptide.Particularly preferred soluble fragment of XOBESIN comprises amino acids30-197, 30-199, 30-207, 30-212, 30-224, 30-231, 30-245 or 30-262 of SEQID NO:2, where it is understood that amino acid 30 is predicted to bethe N-terminal amino acid of the mature XOBESIN polypeptide absent theputative signal peptide.

EXAMPLES

The following Examples are provided for illustrative purposes and not asa means of limitation. One of ordinary skill in the art would be able todesign equivalent assays and methods based on the disclosure herein allof which form part of the instant invention.

Example 1 Use of Biacore Technology to Detect Specific Binding of a TestCompound to Polypeptide Fragment Comprising XOBESIN Extracellular Domain

Biacore utilizes a biosensor technology for monitoring interactionsbetween two or more molecules in real time, without the use of labels.The molecular classes than can be studied are diverse, ranging fromproteins, peptides, nucleic acids, carbohydrates, and lipids to lowmolecular weight substances and pharmaceuticals.

The detection principle is based on the optical phenomena of surfaceplasmon resonance, which detects changes in refractive index close to abiosensor surface. In a typical experiment one of the interactingmolecules is immobilized or captured (here, polypeptide fragmentcomprising XOBESIN extracellular domain) to a flexible dextran layerclose to the sensor surface. The interacting partner (here, testcompound) is flowed across that surface. If an interaction occursbetween the two molecules, there is a resulting increase in signal dueto the increase in mass at the chip surface.

Soluble polypeptide fragment comprising XOBESIN extracellular domain isattached to the sensor surface via amine coupling chemistry. The dextranis activated using N-hydroxysuccinimide andN-ethyl-N′-(3-dimethylaminopropyl)-carbodiimide hydrochloride for 7minutes. Said XOBESIN polypeptide fragment is diluted in 10 mM NaAcetate pH 5.0 at a concentration of 10 μg/ml and injected over theactivated surface for 7 minutes. The surface is then blocked for 7minutes using ethanolamine to remove any remaining esters. A blank flowcell absent said XOBESIN polypeptide fragment is set up in parallel andused as a control surface. The running buffer is HBS-EP (0.01M HEPES pH7.4, 0.15M NaCl, 3 mM EDTA, 0.005% Surfactant P20) and the instrumenttemperature is 25° C.

The test compound is filtered through an Ultrafree-0.5 CentrifugalFilter Device and resuspended in HBS-EP running buffer. The testcompound is then diluted 1:10 in HBS-EP and injected over the saidXOBESIN polypeptide fragment surface and the blank control surface for 1minute at a flow rate of 50 μl/min. The sensorgrams from the receptorsurface and the control surface are aligned and overlayed.

To obtain the specific binding, the control surface was subtracted fromthe active surface comprised of said XOBESIN polypeptide fragment

Example 2 Effect of LIGAND on Muscle Cell Fatty Acid Oxidation

C2C12 cells are differentiated in the presence or absence of 2 μg/mLLIGAND for 4 days. On day 4, oleate oxidation rates are determined bymeasuring conversion of 1-¹⁴C-oleate (0.2 mM to ¹⁴CO₂ for 90 min. Thisexperiment can be used to screen for active polypeptides and peptides aswell as AGONISTS and ANTAGONISTS or activators and inhibitors of LIGANDreceptor.

The effect of LIGAND on the rate of oleate oxidation can be compared indifferentiated C2C12 cells (murine skeletal muscle cells; ATCC,Manassas, Va. CRL-1772) and in a hepatocyte cell line (Hepa1-6; ATCC,Manassas, Va. CRL-1830). Cultured cells are maintained according tomanufacturer's instructions. The oleate oxidation assay is performed aspreviously described (Muoio et al (1999) Biochem J 338;783-791).Briefly, nearly confluent myocytes are kept in low serum differentiationmedia (MEM, 2.5% Horse serum) for 4 days, at which time formation ofmyotubes became maximal. Hepatocytes are kept in the same DMEM mediumsupplemented with 10% FCS for 2 days. One hour prior to the experimentthe media is removed and 1 mL of preincubation media (MEM, 2.5% Horseserum, 3 mM glucose, 4 mM Glutamine, 25 mM Hepes, 1% FFA free BSA, 0.25mM Oleate, 5 μg/mL gentamycin) is added. At the start of the oxidationexperiment ¹⁴C-Oleic acid (1 μCi/mL, American Radiolabelled ChemicalInc., St. Louis, Mo.) is added and cells are incubated for 90 min at 37°C. in the absence/presence of 2.5 μm LIGAND. After the incubation period0.75 mL of the media is removed and assayed for ¹⁴C-oxidation productsas described below for the muscle FFA oxidation experiment.

Example 3 Effect of LIGAND on In Vitro Glucose Uptake by Muscle Cells

L6 Muscle cells are obtained from the European Culture Collection(Porton Down) and are used at passages 7-11. Cells are maintained instandard tissue culture medium DMEM, and glucose uptake is assessedusing [³H]-2-deoxyglucose (2DG) with or without LIGAND in the presenceor absence of insulin (10⁻⁸ M) as has been previously described (Walker,P. S. et al. (1990) Glucose transport activity in L6 muscle cells isregulated by the coordinate control of subcellular glucose transporterdistribution, biosynthesis, and mRNA transcription. JBC265(3):1516-1523; and Kilp, A. et al. (1992) Stimulation of hexosetransport by metformin in L6 muscle cells in culture. Endocrinology130(5):2535-2544, which disclosures are hereby incorporated by referencein their entireties). Uptake of 2DG is expressed as the percentagechange compared with control (no added insulin or LIGAND). Values arepresented as mean±SEM of sets of 4 wells per experiment. Differencesbetween sets of wells are evaluated by Student's t test, probabilityvalues p<0.05 are considered to be significant.

Example 4 Effect of LIGAND on Mice Fed a High-Fat Diet

Experiments are performed using approximately 6 week old C57B1/6 mice (8per group). All mice are housed individually. The mice are maintained ona high fat diet throughout each experiment. The high fat diet (cafeteriadiet; D12331 from Research Diets, Inc.) has the following composition:protein kcal % 16, sucrose kcal % 26, and fat kcal % 58. The fat isprimarily composed of coconut oil, hydrogenated.

After the mice are fed a high fat diet for 6 days, micro-osmotic pumpsare inserted using isoflurane anesthesia, and are used to provideLIGAND, saline, and an irrelevant peptide to the mice subcutaneously(s.c.) for 18 days. LIGAND is provided at doses of 100, 50, 25, and 2.5μg/day and the irrelevant peptide is provided at 10 μg/day. Body weightis measured on the first, third and fifth day of the high fat diet, andthen daily after the start of treatment. Final blood samples are takenby cardiac puncture and are used to determine triglyceride (TG), totalcholesterol (TC), glucose, leptin, and insulin levels. The amount offood consumed per day is also determined for each group.

Example 5 Effect of LIGAND on Plasma Free Fatty Acid in C57 BL/6 Mice

The effect of LIGAND on postprandial lipemia (PPL) in normal C57BL6/Jmice is tested.

The mice used in this experiment are fasted for 2 hours prior to theexperiment after which a baseline blood sample is taken. All bloodsamples are taken from the tail using EDTA coated capillary tubes (50 μLeach time point). At time 0 (8:30 AM), a standard high fat meal (6 gbutter, 6 g sunflower oil, 10 g nonfat dry milk, 10 g sucrose, 12 mLdistilled water prepared fresh following Nb#6, JF, pg. 1) is given bygavage (vol.=1% of body weight) to all animals.

Immediately following the high fat meal, 25 μg a LIGAND is injected i.p.in 100 μL saline. The same dose (25 μg/mL in 100 μL) is again injectedat 45 min and at 1 hr 45 min. Control animals are injected with saline(3×100 μL). Untreated and treated animals are handled in an alternatingmode.

Blood samples are taken in hourly intervals, and are immediately put onice. Plasma is prepared by centrifugation following each time point.Plasma is kept at −20° C. and free fatty acids (FFA), triglycerides (TG)and glucose are determined within 24 hours using standard test kits(Sigma and Wako). Due to the limited amount of plasma available, glucoseis determined in duplicate using pooled samples. For each time point,equal volumes of plasma from all 8 animals per treatment group arepooled.

Example 6 Effect of LIGAND on Plasma FFA, TG and Glucose in C57 BL/6Mice

Briefly, 14 mice re fasted for 2 hours prior to the experiment afterwhich a baseline blood sample is taken. All blood samples are taken fromthe tail using EDTA coated capillary tubes (50 μL each time point). Attime 0 (9:00 AM), a standard high fat meal (see Example 6) is given bygavage (vol.=1% of body weight) to all animals. Immediately followingthe high fat meal, 4 mice are injected 25 μg of LIGAND i.p. in 100 μLsaline. The same dose (25 μg in 100 μL) is again injected at 45 min andat 1 hr 45 min. A second treatment group receives 3 times 50 μg LIGANDat the same intervals. Control animals are injected with saline (3×100μL). Untreated and treated animals are handled in an alternating mode.

Blood samples are immediately put on ice. Plasma is prepared bycentrifugation following each time point. Plasma is kept at −20° C. andfree fatty acids (FFA), triglycerides (TG) and glucose are determinedwithin 24 hours using standard test kits (Sigma and Wako).

Example 7 Effect of LIGAND on FFA Following Epinephrine Injection

In mice, plasma free fatty acids increase after intragastricadministration of a high at/sucrose test meal. These free fatty acidsare mostly produced by the activity of lipolytic enzymes i.e.lipoprotein lipase (LPL) and hepatic lipase (HL). In this species, theseenzymes are found in significant amounts both bound to endothelium andfreely circulating in plasma. Another source of plasma free fatty acidsis hormone sensitive lipase (HSL) that releases free fatty acids fromadipose issue after β-adrenergic stimulation. To test whether LIGANDalso regulates the metabolism of free fatty acid released by HSL, miceare injected with epinephrine.

Two groups of mice are given epinephrine (5 μg) by intraperitonealinjection. A treated group is injected with a LIGAND (25 μg) one hourbefore and again together with epinephrine, while control animalsreceive saline. Plasma is isolated and free fatty acids and glucose aremeasured.

Example 8 Effect of LIGAND on FFA following Intralipid Injection

Two groups of mice are intravenously (tail vein) injected with 30 μLbolus of Intralipid-20% (Clintec) to generate a sudden rise in plasmaFFAs, thus by-passing intestinal absorption. (Intralipid is anintravenous fat emulsion used in nutritional therapy). A treated group(LIGAND-treated) is injected with LIGAND (25 μg) at 30 and 60 minutesbefore intralipid is given, while control animals receive saline. Plasmais isolated and FFAs are measured as described previously. The effect ofLIGAND on the decay in plasma FFAs following the peak induced byIntralipid injection is then monitored.

Example 9 Effect of LIGAND on Weight Gain and Weight Loss of Mice and onMaintenance of Weight Loss in Mice

In the first experiment, 10-week-old male C57BL/6J mice are put on avery high fat/sucrose purified diet for 19 days to promote weight gain;the average body weight at this time is 30 g. The mice are thensurgically implanted with an osmotic pump (Alzet, Newark, Del.)delivering either 2.5 μg/day of LIGAND or physiological saline. The miceare continued on the high fat diet and their body weight was recordedover the following 10-day period.

Weight gain by mice treated with saline in contradistinction to weightloss by mice treated with LIGAND is taken as evidence that in thisinbred strain of normal mice, a continuous infusion of a daily low doseof LIGAND can prevent weight gain caused by high fat/sucrose feeding, ina sustainable way.

Data are expressed throughout as mean±SEM; a p-value<0.05 is consideredstatistically significant. Statistical analysis is typically done usingeither the unpaired Student's t test or the paired Student's t test.

Maintenance of Weight Loss in Mice

In order to demonstrate the ability of LIGAND to maintain weight loss,normal mice are put on a reduced calorie diet to promote weight loss.The reduced calorie diet is continued until the mice lose 10% of theirinitial weight. A second group of mice are continued on the reducedcalorie diet until the mice lose 20% of their initial weight. The miceare then surgically implanted with an osmotic pump (Alzet, Newark, Del.)delivering either 2.5 μg/day of LIGAND or physiological saline. The miceare returned to a normal diet and their body weights are recorded over a10-day period. After 10 days, the outcome wherein mice treated withLIGAND have a lower weight than mice treated with saline is taken toprovide evidence that treatment with LIGAND promotes the maintenance ofweight loss.

Example 10 Assessment of Homotrimer Formation by gAPM1, gC2P, gZADJ-2 orgZADJ-7 Polypeptide Fragment.

Homotrimer formation by gAPM1, gC2P, gZADJ-2 or gZADJ-7 polypeptidefragment is assessed using sedimentation equilibrium in analyticalcentrifuges, a method that determines molecular weight accurately andindependently of other physical factors such as shape.

Candidate gAPM1, gC2P, gZADJ-2 or gZADJ-7 polypeptide fragmenthomotrimer is purified, for example using a protocol comprising a methodof gel filtration such as 16/60 superdex 200 gel filtration column(Amersham). Said purified candidate gAPM1, gC2P, gZADJ-2 or gZADJ-7polypeptide fragment homotrimer protein concentration is made 3 μM in5.7 mM phosphate (pH 7.5), 137 mM NaCl, 2.7 mM KCl. Samples arecentrifuged at 8,000 rpm for 18 hours at 10° C. in a Beckman XL-Aanalytical ultracentrifuge before absorbance is recorded. The data arefit globally, using MacNonlin PPC [Johnson M L et al., Biophys J (1981)36:575-8; Schuster T M et al., Curr Opin Struct Biol (1996) 6:650-8;Hensley P, Structure (1996) 4:367-73; the disclosures of which areincorporated herein by reference in their entirety] to the followingequation that describes the sedimentation of a homogeneous species:Abs=B+A′exp[H×M(x²−x₀ ²] where Abs=absorbance at radius x, A′=absorbanceat reference radius x₀, H=(1−νρ)ω²/2RT, R=gas constant, T=temperature inKelvin, ν=partial specific volume=0.71896131 mL/g, ρ=density ofsolvent=1.0061 g/ml, ω=angular velocity in radians/s, M=apparentmolecular weight, and B=solvent absorbance (blank). TABLE 1 Amino AcidResidues Comprising the Structural Domains of XOBESIN SEQ ID NO: 2Description SIGNAL TRANSMEMBRANE PEPTIDE EC DOMAIN DOMAIN IC DOMAIN 1-2930-275 276-298 299-299EC, extracellular domain; IC, intracellular domain

TABLE 2 APM1, C2P, ZADJ-2 and ZADJ-7 >APM1 polypeptide sequence:MLLLGAVLLLLALPGHDQETTTQGPGVLLPLPKGACTGWMAGIPGHPGHNGAPGRDGRDGTPGEKGEKGDPGLIGPKGDIGETGVPGAEGPRGFPGIQGRKGEPGEGAYVYRSAFSVGLETYVTIPNMPIRFTKIFYNQQNHYDGSTGKFHCNIPGLYYFAYHITVYMKDVKVSLFKKDKAMLFTYDQYQENNVDQASGSVLLHLEVGDQVWLQVYGEGERNGLYADNDNDSTFTGFLLYHDTN (244) >C2P polypeptidesequence: MRIWWLLLAIEICTGNINSQDTCRQGHPGIPGNPGHNGLPGRDGRDGAKGDKGDAGEPGRPGSPGKDGTSGEKGERGADGKVEAKGIKGDQGSRGSPGKHGPKGLAGPMGEKGLRGETGPQGQKGNKGDVGPTGPEGPRGNIGPLGPTGLPGPMGPIGKPGPKGEAGPTGPQGEPGVRGIRGWKGDRGEKGKIGETLVLPKSAFTVGLTVLSKFPSSDMPIKFDKILYNEFNHYDTAAGKFTCHIAGVYYFTYHITVFSRNVQVSLVKNGVKILHTKDAYMSSEDQASGGIVLQLKLGDEVWLQVTGGERFNGLFADEDDDTTFTGFLLFSSP (333) >ZADJ-2 polypeptide sequence:MIPWVLLACALPCAADPLLGAFARRDFRKGSPQLVCSLPGPQGPPGPPGAPGPSGMMGRMGFPGKDGQDGHDGDRGDSGEEGPPGRTGNRGKPGPKGKAGAIGRAGPRGPKGVNGTPGKHGTPGKKGPKGKKGEPGLPGPCSCGSGHTKSAFSVAVTKSYPRERLPIKFDKILMNEGGHYNASSGKFVCGVPGIYYFTYDITLANKHLAIGLVHNGQYRIRTFDANTGNHDVASGSTILALKQGDEVWLQIFYSEQNGLFYDPYWTDSLFTGFLIYADQDDPNEV (285) >ZADJ-7 polypeptide sequence:MGKEDTQETRTEPKMFVLLYVTSFAICASGQPRGNQLKGENYSPRYICSIPGLPGPPGPPGANGSPGPHGRIGLPGRDGRDGRKGEKGEKGTAGLRGKTGPLGLAGEKGDQGETGKKGPIGPEGEKGEVGPIGPPGPKGDRGEQGDPGLPGVCRCGSIVLKSAFSVGITTSYPEERLPIIFNKVLFNEGEHYNPATGKFICAFPGIYYFSYDITLANKHLAIGLVHNGQYRIKTFDANTGNHDVASGSTVIYLQPEDEVWLEIFFTDQNGLFSDPGWADSLFSGFLLYVDTDYLDSISED DEL (303)

1-2 (canceled)
 3. An AGONIST or an ANTAGONIST of XOBESIN activity. 4.The AGONIST or the ANTAGONIST of claim 3, wherein said activity isselected from the group consisting of lipid partitioning, lipidmetabolism, insulin-like activity, free fatty acid oxidation, and weightreduction.
 5. A pharmaceutical or physiologically acceptable compositioncomprising, consisting essentially of, or consisting of the AGONIST orthe ANTAGONIST of claim
 3. 6. A method of preventing or treating anobesity-related disease or disorder comprising providing oradministering to an individual in need of such treatment the compositionof claim
 5. 7. A method of screening of a candidate substance forinteraction with a polypeptide comprising XOBESIN extracellular domain,said method comprising the following steps: a) providing saidpolypeptide comprising XOBESIN extracellular domain; b) obtaining acandidate substance; c) bringing into contact said polypeptide with saidcandidate substance; d) detecting the complexes formed between saidpolypeptide and said candidate substance.
 8. The method according toclaim 7, wherein said candidate substance is an AGONIST or ANTAGONIST ofXOBESIN activity.
 9. The method according to claim 7, wherein saiddetecting step comprises assaying the activity or expression of theXOBESIN polypeptide.
 10. The method according to claim 9, wherein saidactivity is selected from the group consisting of lipid partitioning,lipid metabolism, insulin-like activity, free fatty acid oxidation, andweight reduction.
 11. The method according to claim 8, wherein saidcandidate substance is an AGONIST.
 12. The method according to claim 11,wherein said AGONIST is a composition consisting essentially ofself-assembling homotrimers comprising gAPM1, gC2P, gZADJ2 or gZADJ-7fragments.